PB2430: EVALUATION OF OUTCOME AND SAFETY PROFILE IN HIGH-DOSE BEAM AND BEEAM CHEMOTHERAPY WITH SUBSEQUENT AUTOLOGOUS STEM CELL TRANSPLANTATION IN LYMPHOMA PATIENTS – SINGLE-CENTER EXPERIENCE
Authors: Kinga Krawiec, Piotr Strzałka, Damian Mikulski, Michał Kośny, Olga Racińska, Hubert Sowul, Marcin Kędzior, Wojciech Salamon, Magdalena Czemerska, Agnieszka Pluta, Agnieszka Wierzbowska
Journal: HemaSphere (2023)

Background: The prognosis of patients with relapsed/refractory lymphoma treated with conventional salvage regimens is unsatisfactory, therefore autologous hematopoietic stem cell transplantation (auto-HSCT) preceded by high-dose chemotherapy (HDT) is a mainstay in this treatment paradigm. The safety of auto-HSCT procedures has improved over the years thanks to advancements in supportive care. However, the therapy is still related to many potential side effects, with infections, mucositis, and hematological toxicity being the most common. Although complications like veno-occlusive disease, interstitial pneumonia syndrome, or graft failure occur rarely, they may contribute to treatment-related mortality (TRM), thus creating the need to search for survival-relevant factors. Aims: The aim of the study was to compare the adverse event profile between BEAM and BeEAM regimens as well as to evaluate predictors and treatment outcomes in lymphoma patients undergoing auto-HSCT. Methods: We present a single-center retrospective analysis of patients with lymphoma who underwent auto-HSCT followed by high-dose BEAM or BeEAM between January 2015 and December 2021 at the Department of Hematology and Transplantology in Lodz, Poland. We analyzed 82 patients (median age 52; IQR 38-62) undergoing auto-HSCT in Hodgkin lymphoma (36.6%), mantle cell lymphoma (31.7%), diffuse large B-cell lymphoma (18.3%), and other (13,4%) who received BEAM and BeEAM regimens in 47.6% and 52.4%, respectively. For statistical analysis, we used Kaplan-Meier curves, the log-rank test, Chi-square test with the Yates correction for continuity and the Mann-Whitney U test. Prognostic factors for OS and PFS were assessed using Cox proportional hazard models. Results: During the post-HSCT period 57.5% of patients experienced febrile neutropenia (51.3% vs 63.4% in BEAM and BeEAM patients, respectively; p=0.38), 80.2% - mucositis (69.2% vs 90.5%; p=0.03), 42.5% - bacteremia (50.0% vs 35.7%; p=0.27), and 18.8% - pneumonia (31.6% vs 7.1%; p=0.01). Patients who received bendamustine required more platelet transfusions (p=0.018). In the multivariate Cox regression model for overall survival (OS), CRP on the first day of hospital stay (HR 1.03, 95%CI: 1.01-1.06) and days of grade IV neutropenia (HR 1.15, 95%CI: 1.00-1.32) were predictors of poorer survival, whereas hemoglobin level (Hb) at the first day of hospitalization (HR 0.43, 95%CI: 0.23-0.78) was a protective factor in terms of OS. Similarly, Hb on the first day of hospitalization (HR 0.66, 95%CI: 0.45-0.96) was also a predictor of prolonged progression-free survival (PFS). Moreover, the number of transplanted CD34+ cells, among patients in the entire cohort, correlated negatively with the duration of grade 3 and 4 neutropenia. The log-rank test for OS comparing DLBCL and patients with other types of lymphomas indicated significantly decreased survival for the DLBCL group (p=0.02) (Figure 1). The median PFS for the whole cohort was 57 months, and the median OS was not reached. No differences in PFS and OS between BEAM and BeEAM regimens were proven. Two patients (2.4%) experienced TRM during 100 days after auto-HSCT. Summary/Conclusion: Simple laboratory variables, including Hb and CRP, have proven to be independent prognostic factors of OS of auto-HSCT recipients. Conditioning treatment with BEAM and BeEAM regimens is associated with comparable toxicity of treatment and efficacy. BEAM regimen is correlated with a higher incidence of pneumonia, while BeEAM with a higher occurrence of mucositis. There is no significant difference between BEAM and BeEAM when it comes to survival.Keywords: Bendamustine, Autologous hematopoietic stem cell transplantation, Safety, Lymphoma